<div id="header-container">
    {% include nav.html %}
    <div class="div-fixid center-all" style="color: #ffff00;">
        <strong style="font-size: 40px;" id="bg-text">保持安静</strong>
    </div>
    {% include back_to_top.html %}
    <script>
        function changeBgText() {
            const bgText = document.getElementById("bg-text");
            if (bgText.style.display === "none") {
                bgText.style.display = "block";
            } else {
                bgText.style.display = "none";
            }
        }

        window.changeBgText = changeBgText;
    </script>
    {% include date.html %}
</div>